Discuss Amp frequency response in the Home Theater - Audio / Video forum.
If an amp has a listed frequency response from 20-20,000hz does that mean it cant amplify a 15hz freq? I ...

**Ebux** · **03-27-11, 07:17 PM**

If an amp has a listed frequency response from 20-20,000hz does that mean it cant amplify a 15hz freq? I found a crown ch1 in great shape for a good buy. I would like to use it to drive a sub if it can. Any thoughts would be appreciated.

**lcaillo** · **03-27-11, 07:32 PM**

Without testing its response it is hard to say how fast it rolls off. You can usually assume that a frequency response spec like this defines the limits where the amp is 3dB down from reference, but it can vary greatly, as can the rate at which it falls off. The power bandwidth is another matter, and the amp may have significantly worse response at full power. Perhaps someone has some test results on this amp.

**Ebux** · **03-27-11, 07:48 PM**

Thanks for the info. If I don't hear anything else about it I will let it pass.

**GranteedEV** · **03-30-11, 03:50 PM**

most amps will be flat down to 20hz, and roll off around 7hz.

Either way, you should be able to reproduce 15hz with most amps, at worst it might take some preamp boost. The main thing to realize is that most speakers, even subwoofers, will be very inefficient at low frequencies and that you will need a displacement and power, to get meaningful SPL at these frequencies. Which amp are you looking at?

**Ebux** · **03-30-11, 06:01 PM**

I can get a Crown CH1 for a good buy. I called crown tech support and the guy told me that amp would rolloff 24db per octave below 20hz. The behringers and samsons list 10hz - 20,000hz. So I will probably go that route. Realistically I am wanting to tune an Exodus tempest to 20hz thinking I'll probably get 16 or 17 with room gain. I don't want the amp to be the limiting factor.